The disposal of solid waste material, particularly hazardous waste material, is a continuing problem. Hazardous waste materials must be properly handled to avoid harm to humans and the environment.
Incineration of waste material is a principal method of waste disposal. However, the ash by-product of incineration (commonly called fly ash and bottom ash) can itself be considered a hazardous waste since it may contain heavy metals and other hazardous substances such as arsenic and organic compounds such as dioxins. Such substances are dangerous to humans and will contaminate the environment unless the ash is disposed of in a safe manner, such as in a regulated landfill. Disposal represents an ever-present risk to the environment. It is therefore desirable to provide a method and apparatus for further transforming ash and other hazardous wastes to materials which are suitable for environmentally safe disposal or even useful products. These other hazardous wastes can also include chipped metal waste, such as used paint cans, white appliances, waste steel with waste oil, electroplated materials and aluminum stampings. Also included are asbestos, low radioactivity mixed wastes and polychlorinated biphenyls (PCBs). It is also desirable to provide a method and apparatus for the transformation of solid waste materials considered to be extremely hazardous such as "sharps" and other solid medical wastes.
Methods and apparatus for reducing waste materials to separable constituents have been proposed in the past, but none are known to be widely used commercially. Deficiencies in high temperature waste treatment processes have limited their utility. Difficulties in processing the effluvia of the combustion process which are themselves hazardous have required costly special treatment. Other deficiencies are that gas/electrode plasma systems used for heating the hazardous waste have very limited duty life, i.e., an average life expectancy of 50 hours.